Heres how I do it.
Level the neck. Also make sure that the fretboard is level, as in not lumpy anywhere, dont just assume it is, I've fallen afoul of that before and it just makes the fret dress a bust. If it isnt, the frets in that area are going to need special attention to get them in line (literally)
Take a permanent marker, draw a line on the top of each fret.
Get a fret file, a proper one (a sharpening stone can do the job but leaves a surfaces thats harder to deal with). File them down till theres no more marker markings anywhere.
Take your DIAMOND fret file. Buy one. They rock. Try with a conventional crowning file as well if you must, then see the difference in how easy it is and thank me later. Crown frets. Theres a certain black art to it due to the radius of the board, but its not too hard. I use the change in texture/roughness/whatever of the surface between the two files as an indication as to what areas have been fully crowned and not; dont overdo any area of any fret or its start-again-o-clock)
Smooth out most of the marring of the surface (the diamond files dont leave a perfect shine by any stretch) with ~600 grit wet and dry.
Shine the fret up but good with MICRO MESHES. Best bought from modelling suppliers (like as in making little toy planes and shitee - for some reason these people find this stuff, which was developed to polish aircraft windows, useful and have cheap supplies of it, unlike the likes of stewmac, who charge an arm and a leg for it). These will give them a mirror finish (but you need the wet and dry in between, because they arent coarse enough to deal with the surface the diamond file leaves)
String up, test with thorough playing or a fret-height tester (or improvised fret height tester - you need anything thats got straight hard surfaces that you can rock over 3 frets at a time all over the board), and then if there are still any high frets (which if you did the above properly there shouldnt be, but it happens from time to time) wedge the strings up with something and use a conventional metal crowning file under the strings to level it - these do leave a smooth surface, but take a lot of work to remove little material). Be careful not to take too much off, or youre just gonna have to do the next fret too (and maybe the next and the next and so on)
Its more than a hundred quid in stewmac tools and peripheral shitee, probably about 150, but its well worth it for being able to get good frets whenever you need them - I'd get them even if I wasnt a tech.
Oh, of course, now you know I (also) work as a tech, maybe youre just going to have to take it on faith that my method isnt half assed ;). This shitee aint that easy y'know! (But welcome to the club of people that went 'screw it, I can do it myself' - thats the only real difference between techs and people that take guitars to techs).
